Lap



A. SCHULTZ Feb. 7,A 1939.

LAP

n Filed Jan. 17, 1938 Patented Feb. 7, 1939 r i UNITED STATES PATENT OFFICE LAP Albert Schultz, Chicago, Ill., assigner to Boyar- Schultz Corporation, Chicago, Ill., a corporation ofIllinos l Application January 17, 1938, Serial No. 185,293

Claims. (Cl. 51-184.1)

kThis invention relates to a lap andto a lapV holder. It has for one object to provide a lap, the major portion of which is permanent and upon which Aa removable wearing portion may be positioned. Another object is Vto provide such an assembly in which both the permanent part and the removable part of the lap are shaped to make certain theirproper assembly. Another object is to provide a lap and a lap support or holder in which the support is intended to be rotated in one direction and in which the lap and the sup'- port are so shaped that they can only be assembled in proper relation with respect to the direction of rotation of the holder. Other objects will appear from time to time in the course of the specication and claims.

Theinvention is illustrated more or less diagrammatically in the accompanying drawing, wherein- Figure 1 is a side elevation of the lap land Figure 5 is a transverse sectional detail takeny at line 5, 5 of Figure 4.

- Like parts are indicated by like characters throughout the specication and drawing.

I is a'work piece having a perforation 2. 'Ihe lap is shown as in position for finishing or lapping the inner surface of the perforation 2.

3 is a tool holder of any desired design, arranged to receive the lap and the lap support removably and to rotate.

As shown the lap comprises a support member 4,` which may or may not have a somewhat enlarged or thickened section 5. The support whether it comprises one or several diameters is preferably provided with a shoulder portion 6, against which the lap portion may be seated. The support is also provided with a slot 'l which at its'inner end may be rounded as at 8. In general the slot may be shaped in any way desired. At its outer end the support may be beveled as at 9, and one corner of one-half of the support is cut away or sloped as at l0.

'The lap proper comprises a sleeve II provided with one or more perforations I2 rwhich may be arranged in any desired manner but as here shown are arranged in several rows. The sleeve yis so shaped that a slot' or open portion I3 remains along one side, and along that side the sleeve is provided with an inwardly bent edge I4 which as shown, particularly in Figure 5, ts into 5m.

the slot'I. At its outer end or edge and on the side which carries the inbent portion I4, the sleeve is provided with an inwardly bent or inclined portion I5. The inclination of the portion being substantially the same as that of the cut away portion I0 on the support. 'Ihus when the lap sleeve is positioned upon the lap support, the portion I5 rests against the surface IB. This portion also prevents putting the sleeve upon the support in any other position. If the sleeve were l5 reversed end for end it could not be put upon the support because the member I5, projecting inwardly, would contact the support and prevent further movement.

A screw I6, may if desired, be positioned in one side of the support as shown in Figure 4.

It is positioned in one-half of the support; extends into the slot 1 and may be rotated to bear against the other half of the support. In this manner it can be used to spread the two halves 25. of the support if desired. It may also of course be backed ofi so that it does not spread the halves. n

The use and operation of my invention are as fOllOWSZ In general the support or mandrel 4 is inserted in some sort of tool holder or means for holding and driving it. That is to say for rotating it. 'Ihe removable sleeve is positioned on the mandrel as shown in the drawing and the presence 3 of the inwardly bent portion I5 prevents the sleeve from being put on improperly.

As shown, in Figure 5 in particular, the direction of rotation of the mandrel is indicated by the arrow. It is important that the sleeve be so 40 put on that the edge along which the ange I 4` is positioned shall lead in rotation and that the free edge adjacent the open portion I3 shall trail. This arrangement has the tendency oi causing the sleeve to embrace the mandrel closely. If

rotation were in the opposite direction, or if the sleeve were inverted so that in any Way the edge adjacent the open portion I3 were leading, the free edge would engage the work piece and would be spread or forced away from the mandrel, with the result that either improper lapping would occur or entirely improper functioning of the device would occur. Consequently it is important to make certain that the sleeve is so positioned on the mandrel that the edge which leads is the one adjacent the iiang'e or inbent portion I4. That result is accomplished by providing the inwardly bent portion l5, which since it projects ow downwardly and outwardlyto the sleeve andv are thus distributed about the mandrel, sleeve and the interior of the work piece. may be covered with lubricant if desired and the lubricant may be carried about and distributed into the perforations i2 and elsewhere. A sleeve of the present design may be used with a modified mandrel andthe inventionis not limited to exact detailsof the mandrel shown.

1. Ina lapping device, a driving and supporting member, a flexible metallic sleeve, having an inbent longitudinal ange thereon, said sleeve constituting an operating member removably mounted onvsaid drivingmember, said driving member having a longitudinal passage formed therein, said flange adapted toextend into said passage removably toengage the driving member, said sleeve extending about the drivingfmember, one longitudinal edge of the sleeve being free, an inbent portion on one end of said sleeve adapted, when the sleeve is imposition on the supporting member, to contact it and to preventv improper mounting of the sleeve on said supporting member, and a depression in the outer end of said supporting member into which said inbent portion fits whenthe sleeve is in position on the support.

'2. In a lapping device a drive, a. supporting member generally elongated, said member beingV divided into parts by a slot formed through it andextending from one end longitudinally inward,

the outer end of one of said parts beingcut off` and a removable metallic sleeve, slotted from end toiend and provided with an inwardly bent longitudinal ange, adapted to enter said slot, when the sleeve is positioned upon the support, a portion of thel outer end of said Lsleeve being bent inwardly, said inwardly bentV portion havingI approximately the same inclination* as the said cutoff-'portion of-saidsupport.` f

It may be convenient to put' The entire sleeve the Y the mandrel, the proportion of the sleeve to the Vmandrel being such that it does not extend entirely about the mandrel, the leading edge of one of said mandrel sections being cut away, said sleeve provided with an inwardly bent endpor-V tion of ysubstantially the same inclination and size as said cut awayedge, said inwardly bent portion being adapted when the sleeve is in position on Vthe mandrel to lie against said cut-,away portion.` j `v 4.; In combination inra lapping device a man'- drel havinga longitudinal slot extending from its outer` end, the slot being enlarged at itsV inner end, a portionv of Vthe outer end of the mandrel being` cut oiv adjoining said slot, and a lap adapted to be removably 'mounted on the mandrel, said lapY conforming generally in shape to the mandrel and being slotted from end to end, an inbent tongue on said lap shorter than said lap and an inbent portion on said la-p adapted, when the lap is in posi-Y tion on the mandrel, to'over-lie such cut-off por-f tionof the mandrel and to prevent improper posii tioningof the lap on the mandrel. v

5. In combination in a lap a mandrel having a longitudinal slot formed in it extending from one endthereof and an enlargement at the inner end of the slot, an outwardly projecting shoulder. in said mandrel intermediate the ends of the slot,

thei mandrel being otherwisek smooth-sided, thevr I mandrel having a portion of its end adjoining said vslot cut ofi and providingN thereby asurface angularly disposed with respect tothe outer' end ofl the mandreLga lap removably positioned 'upon said mandrel, said lap being generallycylindrical ini shape and formefdof' asingle discontinuous piece, a tongue formed integrally with theflap, at

one edge and being inbentV toward they center of 

